I've got a Synology NAS and I keep OneDrive for documents I might need in case of emergency.
Dropbox has no reason to exists for me. Firstly, they want to force me which filesystem to use on my Linux box, secondly, I already have plenty of GBs on Google Drive and MS OneDrive, so why would I need another service is beyond me. I mean, it's not like Dropbox is a safe encrypted alternative to GDrive or OneDrive anyway...